I have tried 270.61,275.33,280.26,285.62 and with all of them games crashes randomly. There is no %100 reason. For example; wheni start game, when i changed graphic settings, after 10 minutes of playing game etc. game crashes. I'm experienced that with Deus Ex: Human Revolution,Audio Surf, Bulletstorm and Battlefield 3. Also with some games having fps drops/stutters like Bulletstorm (UE 3), Battlefield 3 (Frostbite 2), GTA IV (Rage Engine), Alice Madness Returns(UE 3).

Crashing might stop, when you give the ventilator 100%. It did in my case. Download msi afterburner and set the ventilator on auto and drag the switch to the right side. Press apply at the bottom of the sreen. The problem could be solved. By the way: It also might help to dustclean your videocard.